Notes from Nursery Greenhouse and Turf Continuing Education Conference – 2016

Nursery Greenhouse and Turf Continuing Education Conference - Presented by Helena Chemical Company
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Summaries below were based on notes taken from the Nursery Greenhouse and Turf Continuing Education Conference, held in Tyler, TX (June 21, 2016), put on by Helena Chemical Company.


Herbicide Fate

by Dr. Brad Shaver

Incorporating Biopesticides into a Conventional Program

by Dr. Debbie Sanders

Overview of Revisions to EPA’s Agricultural Worker Protection Standard

by Mark Evans

Mites & Pest Management on Ornamentals

by Dr. Carlos Bogran

Interpreting Pesticide Labels and Sprayer Calibration

by Dr. Casey Reynolds

Herbicide Fate

Dr. Brad Shaver
Helena Chemical Company

Things that can happen to an active ingredient:
  • photolysis
  • runoff
  • sorption
  • volatilize
  • leaching
  • etc.
Factors affecting foliar uptake:
  • volatility
  • washed off leaf
  • remain on the surface
  • photolysis
  • penetrate cuticle – absorbed by lipids
  • penetrate and move between cells (apoplastic)
  • penetrate and move through calls (symplastic)
Root uptake can be affected by:
  • volatility
  • photodegradation
  • leaching
  • runoff
  • biodegradation
  • placement
If a product instructs that rainfall or watering down is required after application, the product could degrade on the soil surface if you don’t water it down. Need to get a.i. down to the roots.

Transportation processes - herbicides can end up moving directly off site via:
  • Volatility
  • Leaching
  • Runoff
  • Drift
Volatility can account for 90% loss of active ingredient (NCSU)!
Drift, such as atmospheric losses and off-site movement. Affected by environmental conditions and application techniques.
Runoff affected by climatic conditions, soil factors, chemical properties, site and application management. Be extra cautious of runoff to ponds/tanks, can kill aquatic life and if used for irrigation, can destroy an entire crop.

Different ways chemicals can interact with your leaf surface or soil particles:

Some terminology:

The process of how a chemical associated with a surface
Accumulation (adhesion) of a substance onto another surface (soil, air, water) (chemical adsorption is passive)
Uptake or intake of particle

Convection: Mass flow of chemical with soil solution
Diffusion: slow movement of chemical molecules over short distances

Risk of runoff decreases with time after application.

Soil Conditions that impact risk of runoff:
  • Texture
  • Compaction
  • Slope
  • Organic matter content
  • Soil water content (i.e. if the soil is already saturated/wet, then you have a higher chance of runoff if you spray)
Chemical properties of the active ingredient that impact risk of runoff:
What is Koc (Sorption coefficient)?
  • Affinity of herbicide to bind to soil and organic matter
  • Can be found on SDS sheet of active ingredient
  • Lower Koc = high leaching/runoff potential
  • High Koc = tightly bound
  • Glyphosate: Koc 24,000
  • Indaziflam = 450 Koc
  • Simazine = 130 Koc
Less than 500 Koc considered high risk for leaching.
Why it’s so important to look at the label for things like buffer zones or warning for leaching

Leaching is:
  • movement of herbicides through the soil
  • downward, lateral, and reverse leaching
  • some leaching is required
Site and Application Management:
  • Proper application rate, volume and timing
  • Plant residues (lot of plant residue on the surface that will stop the product from moving down)
  • Vegetative buffer strips
RTFL – Read the Freaking Label

Types of A.I. Degradation

  • Primary means of herbicide degradation, especially in the soil
  • Microbes metabolize & use as a source of energy
  • Most are biotic
  • Most affected by soil:
  • Temperature
  • Moisture
  • Oxygen
  • Application history (xenobiotic): could get enhanced microbial degradation if there’s a history of applying the same active over and over again. Build up populations of microbes that degrade that product – Not good if it’s breakdown down a.i. before reaching the plant!
Chemical degradation:
  • Chemical reactions/breakdowns
  • Hydrolysis
  • Oxidation
  • Complexing
Chemical degradation is affected by:

  • Soil chemical properties
  • Herbicide formulation

Herbicide persistence in the soil actively relies on a threshold level of a.i. and is measure by T1/2 (half-life)

Examples of Herbicide Half-Lives:
2,4-D: 9 days
Pendimethlin: 40 days
Glyphosate: 44 days
Indaziflam: 150 days
Triclopyr butoxyethyl ester
Field Dissipation: 39 days
Anaerobic: 26 days
In water: 0.5 days
Triclopyr butoxyethyl salt
Field Dissipation: 139 days
Anaerobic: 1600 days
Two products containing the exact SAME active (i.e. Triclopyr butoxyethyl), but slightly different formulations (ester vs. salt), can drastically increase half-life the product (39 days vs 139 days).

Need to weigh out benefits of longer persistence with ‘cost’ with leaching possibility.

Incorporating Biopesticides into a Conventional Program

Dr. Debbie Sanders

Reasons growers start using bio-pesticides:
  • Stop resistance
  • Decreases costs
  • Consumer demand – consumer wanting better price for crops and top-down pressure from retailers (i.e. no neonics)
  • Safety concerns for workers, consumers & environment – many bio-pesticides are exempt from tolerances and Max residue limits
  • Low restricted entry intervals and pre-harvest intervals
  • Complex mode of action prevent or delay development of resistance to synthetic pesticides
  • Wider selection of alternatives for organic growers
  • Better compatibility with beneficial arthropods
Preconceptions and Myths of Bio-pesticides:
  • they do not work as well as synthetics
  • they are incompatible with synthetic products
  • they do not have a good shelf-life: although often true, the shelf-life is mentioned right on the label
  • single applications are enough
  • we do not really know how they work
  • they never cause phytotoxicity
General best-use practices:
  • Think proactive
  • Detect pests as soon as possible
  • Intervene early in the pest cycle, at low to medium pest pressure
  • May not perform well under high pest pressure
  • Obtain accurate diagnosis of the problem
  • Select the right products for the right disease or pest
  • Follow label instructions: rates, timing, safety, storage
Use appropriate formulation for the job:
  • WP, WDG, ES, EC, G
  • Spray, sprench, dip, drench, soil incorporation, top dress
  • seed treatment
Test new products small scale before adoption:
  • Set-up a good comparison of current vs test treatments
  • Integrate rather than replace
  • Gauge the risk of phytotoxicity
Proper application:
  • select the most appropriate application method
  • select the right equipment for the job
  • keep your equipment clean
  • calibration and maintenance of equipment are critical
  • know when and how often to apply
  • good coverage & proper concentration are critical; most do not act systemically
  • Pay attention to self life and storage conditions/limits
  • Consider compatibility with other products and practices
  • Tank-mix or rotational compatibility can help economize programs and increase efficacy. i.e. BioWorks BotaniGard tank mix compatibility sheet.
  • find alternatives or time applications to overcome incompatibilities
  • quick knock-down or clean-up by the chemical, and extended protection by the bioinsecticide

BioWorks also has a beneficial insects compatibility chart with their products.

Attributes of Bio-pesticides:
  • Heed the differences with synthetic products
  • Contact or ingestion is necessary; few systemics
  • Preventive vs curative
  • Slower speed of kill
  • Complicated modes of action mean less chance of resistance
  • More compatibility with BCAs
  • More limiting storage conditions and shelf-life

Exampls of bio-pesticides

Beauvaria bassianaAzadirachtin
  • Very effective against whitefly
  • Mortality not immediate, takes 3 – 7 days
  • Sporulation is not a measure of efficacy
  • Insect growth regulators extracted from neem seeds
  • Actives as insect growth regulator, can act as feeding and oviposition deterrent, repellent.

Pre-emulsified oils go into solution better and have small particles, so they spread more, and greater chance of covering the insect. Better respiration and transpiration on your plant.

Bio-Fungicides suppress plant diseases:

  • Acts via two or more modes of action
  • Act preventatively rather than curatively (most)
  • Are effective at low to moderate disease pressure
What Bio-pesticides CAN’T do:
  • Offer 100% protection – no pesticide does
  • Cure diseases (few exceptions)
  • Work in environmental extremes
  • Work at high disease pressures
  • Last indefinitely
  • Make a bad grower good

General characteristics of soil/root biofungicides:

  • May act quickly or after a lag period
  • Typically act via 2 or more modes of action
  • Good distribution and proper concentration are critical

If populations of the pest/disease are really high, consider first a knockdown via synthetic products, and then use biopesticide for continued suppression.

Tips for starting your own biopesticide program:

1. Think proactive or preventative: exclusion, sanitation, environment

2. Properly identify the disease and the pest issues (don’t assume)
  • Determine which products, practices, and timing you are currently using for these and their costs
  • Define what success looks like
  • Contact manufacturer, other growers, and extension for advice
  • Test new products on a smaller scale before going “all out”
  • Document your tests
  • Keep an open mind

Overview of Revisions to EPA’s Agricultural Worker Protection Standard: 40 CFR 170

Mark Evans
Texas Department of Agriculture

Please Note: These are notes taken from the talk given by Mark Evans. By providing these notes, we are in no way guaranteeing that they are accurate. Please consult EPA, TDA, or the Texas A&M Agricultural and Environmental Safety Unit resources or personnel for accurate information.

Key Links:

Regulation Revisions Comparison Chart
Comparison of current regulations and new regulations in PDF format, published by the EPA.

Pesticide Application Data Sheet (2015)

Texas Pesticide Application Data Sheet can be downloaded at:

A lot of revisions not effective until January 2017 and some until January 2018.

TDA required to do a certain number of inspections every year

  • In general, will call before they come to visit; gives you time to ‘get ready’. But you should always be ready.
  • Can do unannounced visits; usually the result of a complaint. Should be ready with your records and everything in place.

Definition of immediate family has expanded to:

  • grandchildren, grandparents, aunts, uncles, nieces/nephews, step-parents, first cousins
Three Main Take-Aways:
  1. Instead of having training every 5 years for workers and handlers, you need to do ANNUAL training
  2. Need to keep record of all pesticide applications made on the farm for 2 years and all applications need to be available to your handlers, workers/employees. Need to have SDS available (for all chemicals/pesticide A.I.s) for workers/employees/handlers.
  3. Expanded definition of immediate family, which a lot of the “provisions” do not apply to.

DISPOSE – Don’t take the risk of storing stuff you know you’re never going to use. Dispose of it appropriately. We used to have a program (Free) for annual pickup of products that growers wanted to dispose of – it was cut a few years back due to budget cuts, but may be re-instated next legislative session.

Who is covered by the Rule (WPS):
  • Agricultural employers on crop-producing establishments
  • Commercial pesticides handling establishment employers
Who is protected?
  • Farmworkers
  • Pesticide handler
  • Other persons during pesticide application
Relationship between pesticide labeling & WPS
  • The labeling has product-specific requirements to protect workers and handlers
  • WPS has instructions on how to implement the requirements
  • WPS also has general protections too lengthy to place on every label

WPS Revisions
Goal: reduce risk of pesticide exposure

Pesticide Safety Training:
  • Pesticide training every year
  • Expand training content (not currently ready, so may be delayed till January of 2018, when WPS publishes the new material)
  • Require recordkeeping of training
Who is qualified to do the training:
  • Current: Handlers can train other workers
  • Revision: Handlers are no longer qualified. They need to be a certified application (i.e. private/commercial applicator license or have an EPA approved Train-the-Trainer program which is not yet developed). Starting January of 2017.
Warning Signage Revision:
  • Outdoor nursery production: need to post with “danger” when sprayed with something that has 48 hr or longer REI
  • Greenhouse operation: Any REI greater than 4 hrs, posting of “danger” is required.
  • Less than those REIs, can just tell verbally (i.e. morning meeting with workers)
  • STILL need to post in central display/information center and leave it there for 30 days, and keep record of it for 2 years.

Employees requiring respirators for applications will have to pass a “fit test” and medical evaluation

Minimum age is now 18

Application Exclusion Zones (AEZ) in Outdoor Production could be up to 100ft beyond where the application is taken place that is included in the REI area.

Decontamination supply requirements:
  • Provide 1 gallon of water for each worker and 3 gallons for each handler
  • If handler is using a product that requires eye protection, eye flush water must be immediately available at each mix/load site for handler eye flushing

January 1, 2016 – Revised WPS final rule becomes effective
January 1, 2017 – Compliance is required with most of the revised WPS requirements


Richard Pont
Nancy Fitz

Mites & Pest Management on Ornamentals

Dr. Carlos Bogran


  • Not insects
  • They have eight legs
  • Body divided into two parts
  • Large group: 50,000+ species

What mites do?

  • Many are beneficial that feed on dead stuff or fungi and help break it down
  • There are mites that are also parasites

Two major groups: Parasitiformes and Acariformes

  • Acariformes includes the Prostigmata, which includes most of the plant-feeding mites.
  • Beneficial mites and predatory mites have some distinct shapes
  • Plant-mite have short stubby legs, predatory mites have longer legs (need good legs to go hunting)
Phytophagous mite species:
  • Spider Mites (Tetranychidae)
  • False Spider Mites (Tenuipalpidae)
  • Gall and rust mites (Eriophydidae)
  • Broad mites (Tarsonemidae)
  • Acarid mites (Acaridae) (pollen feeding, ones you’ll see in your pantry)
  • Other phytophagous mites:
  • Siteroptidae, penthaleidae, Tydeidae, Tuckerellidae

Citrus leprosis or nail head rust is vectored by mites
Recent invasive: the red palm mite

  • 31 genera, 300+ species
  • 17 genera & 63+ species in Florida
  • Fourth pair of legs not used for walking
  • Feed on fungi, algae, leaves, stems & fruits
  • even smaller than spider mites (~20% size of spider mites)
  • egg surface has distinct little white pumps in them that you can see under the microscope
  • Cause leaves to deform in order to protect themselves
  • Once the damage is done, you need very good coverage in order to get them
  • Best solution (if economic) is to remove damaged plants, because they do not move quickly and controlling established population is very challenging
  • often brought in from cuttings of mother plants or were not detected upon initial spread
Tetranychidae (spider mites):
  • 71 genera, 1,300+ species
  • Feed on leaves, stems & fruit on many plants
  • Feeding damage: yellowish to bronzing, defoliation, white or gray spots on leaves
  • Advised to use a microscope or hand lens as eggs are very hard to see with the naked eye. Detecting spider mites eggs is highly advantageous.
  • Color of the mite can be misleading. Coloration changes depending on the plant they are feeding on. Males are required for most species identifications.
Two-spotted spider mite (T. urticae):
  • Wordwide one of the top pests
  • 900 host plants
  • Life cycle is between 8 to 40 days. That’s almost one week, when it’s really warm, you can have another whole new populations.
  • They molt quickly, leaving around exuviae
  • Temperature range: 12 and 40ºC (57 – 104 ºF)
  • Days from egg to adults:
    • 8.3 days (25/35ºC; Night/Day)
    • 28.2 days (temp 10/20ºC; Night/Day)
  • Sex ratio (female to male) = 3:1

Spider mites are like an avalanche! When the population gets going, their population grows very rapidly.

Growing indoors: temperature management is part of spider mite control. It will be really hard to control spider mites if temp is high, because you are getting really high reproduction

Warmer and drier areas in the greenhouse had higher mite infestations (Poncet et al. 2007)

Can have different populations within a greenhouse that are resistant to different acaricides.

Can get very little movement of spider mites between populations within a greenhouse.

If you have no control, often have poor acaricide coverage

Excellent products:

  • Floramite, Pylon, Avid, TetraSan, Sanmite, Akari, Insecticidal Soap, M-Pede, Judo
  • Good products: Shuttle-O, insecticidal oils/soaps

Always rotate modes of action group numbers: Even if active ingredients are different, and the Mode of Action is the same you may be selecting for insecticide resistance

Potential reasons for weak control:
  • Crop size to amount sprayed
  • Contact and residual activity
  • Crop-host plant size, architecture
  • Physical factors in the environment during and after application
  • Formulation and application rate
  • Insecticide resistance
Predatory mites: Phytoseiidae:
  • Predators of mites, thrips and whiteflies
  • Can survive with minimum prey, can feed on nectar/pollen until prey are around again
  • Phytoseidae Diversity: some that feed specifically on spider mites, or mites that are more broad-spectrum
  • How to release predatory mites can be challenging. Very easy to put things in irrigation water or in a boom sprayer, but method of predatory mite application is much more challenging.

Koppert Side Effects Database: Some chemicals can be used in addition or in conjunction with biological control.

Manipulating crop fertilization to enhance management:
  • Does reducing the amount of fertilization reduce the number of two spotted spider mites?
    • Yes.
  • Could use 50% the fertilization rate in some instances and still get similar production and less pressure from spider mites
  • When providing less fertilization, spider mite populations were also lower. Don’t want to go so low on fertilization that it impacts plant growth.
Eliminate sources of pest infestation:
  • Sanitation in and around production areas
  • Inpsection of incoming plant materials
  • Eliminate old-unsalable plants
  • Live or other barriers to minimize colonization
  • A lot of these insects come in via insect. Anything to block wind/air flow into production areas.
  • know when pests first colonize, where they are located and their population levels
  • requires extra time/effort until it becomes routine and yields results
  • use monitoring tools such as yellow sticky cards
  • determine target pests, combine passive & active monitoring (traps/inspection)
  • invest appropriate time and effort; frequency, consistency are keys
  • train staff
  • take records!
Pesticide administration:
  • use Mode of Action for rotation and avoid pesticide resistance
  • select products based on current pest population levels to best match the application with its right biological target
  • Calibrate often to determine if the right amount of a.i. is reaching its target (i.e. use water sensitive cards)
  • use selective products first to avoid secondary pest outbreaks
  • Eliminate ineffective applications and product combinations; check before and after to ensure that the product was effective
Integration of tools and tactics:
  • build experience on a simple crop system
  • obtain and review updated, reliable plant health information
  • determine which products and biological control strategies may be compatible
  • identify quality suppliers, application and delivery systems
  • determine rates and best time to use
  • check effectiveness and quality, re-asses

Interpreting Pesticide Labels and Sprayer Calibration

Dr. Casey Reynolds
Texas A&M AgriLife Extension

Excellent resource for interpreting pesticide labels – Crop Data Management Systems: – Newly updated website. Have over 100 weeds up there.

  • We often just glance at the label for the rate, where we can spray it and what it will control
  • The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA): established in 1947 and states that pesticides moving in interstate commerce must be registered with the USDA
  • In 1972, Congress passed the Federal Environmental Pesticide Control Act (FEPCA), which says that the federal government will be involved in all aspects of pesticides to include manufacturing, shipment, application, storage, and disposal.

When you receive the product, you are in a contract with the federal government that you will abide by the label.

FEPCA impacts on applicators: The pesticide label is a legal document and using the product in a manner inconsistent with the label is a violation of federal law

If you are applying labels correctly, you have pesticide labels, pesticide records, etc. then you’re good. Much better than not being sure whether you have labels or when you last sprayed, especially for protection against lawsuits.

Dr. Casey gets a call at least once a year from attorneys for potential misuse of pesticides.

All pesticides must be classified as either general use or restricted use. Restricted use pesticides can only be applied by, or used under, the direct supervision of a certified applicator.

Persons that do not obey the law will be subjected to penalties to include fines and/or jail terms:

  • Civil penalties up to $5,000 per offense
  • riminal penalties up to $25,000 and/or up to 1 year in prison

Dr. Reynolds hasn’t seen a single person go to prison (since he started in 1996).

Very few cases actually go to court, but can happen.

Pesticide labels often contain a large amount of pertinent information relative to product application and success.

Trade Name: The commercial name given by a company.


  • Flowable or Aqueous Suspension (F, L, or AS)
  • Emulsifiable concentrate (E or EC)
  • Water-soluable Concentrate (WSC)


  • Water dispersible Granule (WDG)
  • Dry flowable (DF)
  • Wettable Powder (WP or W)
Why is it important to know dry vs. liquid:
  • percent of active ingredient
  • performance of product
  • preference of applicator: using dry vs liquid have different pros and cons. i.e. it’s a pain to clean liquid pesticide , whereas granules are much easier to sweep up. Some powders have more “dusts” and some people may not like that (even if you have a good respirator).
  • cost of active ingredient: sometimes can be huge difference in cost of solid vs liquid.
Interpreting Pesticide Labels:
  • Calculating rates of dry formulations
  • When using dry formulations the number of the label refers to % a.i. by weight.
  • Liquid formulations
    • refers to lbs of active ingredient per gallon of product

Area * Rate * Analysis to calculate how much product you need to put out (assumes the label does not give you a use rate).

Sometimes the “Formulation” (i.e. Disarm C, Disarm M, or Disarm 480 SC) may be related to items under the ingredients list. Look at formulations and also lbs of active per gallon of different products to determine most economic option.

PPEPerson Protective Equipment
REI – Restricted Entry Interval

When you are sending employees out to spray, be sure to provide employees with the PPE on the insecticide labels.
– Disgruntled ex-employees and even ex-wives often call regulators (i.e. TDA) to inform them of lack of PPE.

What are some things (other than rate) that we can change to increase effectiveness of sprays?
  • Spray Wand
  • Nozzle Selection
  • Timing
  • Spray Volume
  • Droplet Size

Be sure to check label for pesticide compatibility. Most products are safe to spray with each other, but check the label for that.

Spray Adjuvants:

  • The label will advise certain surfactants that will drastically increase control
  • Be sure to use the right type of adjuvant for the product you are spraying

Label will tell you what species it can control and what rates to use.

Precautions and suggestions:

  • i.e. mowing prior to or immediately after product application
  • will provide other tips of do’s or don’ts to increase chance of effective application

Irrigation/Rainfall: will advise whether AI needs to be watered down to the roots in order to be effective.

Where is the target organism? Is your insecticide getting to your target?

Temperature: Not going to get control when it’s cold for weed control

Sprayer/Spreader Economics: How can we change spray volume (GPA)?
  • Speed
  • as speed increases, spray volume (GPA) decreases, and vice versa
  • Pressure
  • As pressure increases, spray volume (GPA) increases, and vice versa
  • Nozzles
  • Nozzle spacing
  • Nozzle selection

Following equation for boom sprayers with multiple nozzles. Does not work with single nozzle sprayer:
GPA = (GPM x 5940)/(MPHxNSI)
or GPM – (GPA x MPG x NSI)/5940

Gallons per acre
Gallons per minute
Miles per hour
nozzle spacing in inches

Nozzles with larger spray volumes and larger drop sizes will have less drift.

Step 1. Collect information information from above:

  • tank volume: 250 gallons
  • nozzle spacing: 20 inches
  • easy to get consistent speed (timed steps or speed on a vehicle)

GPA = 0.1 x 5940 / 4 mph x 20”


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